TestBZip2BitInputStream.java

package org.itadaki.bzip2;

import static org.junit.Assert.*;

import java.io.ByteArrayInputStream;
import java.io.IOException;

import org.itadaki.bzip2.BZip2BitInputStream;
import org.junit.Test;

/**
 * Tests BitInputStream
 */
public class TestBZip2BitInputStream {

    // Boolean

    /**
     * Test reading 8 zeroes
     * 
     * @throws IOException
     */
    @Test
    public void testBooleanFalse8() throws IOException {

	byte[] testData = { 0 };
	BZip2BitInputStream inputStream = new BZip2BitInputStream(new ByteArrayInputStream(testData));

	for (int i = 0; i < 8; i++) {
	    assertFalse(inputStream.readBoolean());
	}

    }

    /**
     * Test reading 8 ones
     * 
     * @throws IOException
     */
    @Test
    public void testBooleanTrue8() throws IOException {

	byte[] testData = { (byte) 0xff };
	BZip2BitInputStream inputStream = new BZip2BitInputStream(new ByteArrayInputStream(testData));

	for (int i = 0; i < 8; i++) {
	    assertTrue(inputStream.readBoolean());
	}

    }

    /**
     * Test reading a single 1 in any position as a boolean
     * 
     * @throws IOException
     */
    @Test
    public void testBooleanSingleOne() throws IOException {

	for (int i = 0; i < 8; i++) {

	    byte[] testData = { (byte) (1 << (7 - i)) };
	    BZip2BitInputStream inputStream = new BZip2BitInputStream(new ByteArrayInputStream(testData));

	    for (int j = 0; j < 8; j++) {
		if (j == i) {
		    assertTrue(inputStream.readBoolean());
		} else {
		    assertFalse(inputStream.readBoolean());
		}
	    }

	}

    }

    /**
     * Test reaching the end of the stream reading a boolean
     * 
     * @throws IOException
     */
    @Test(expected = IOException.class)
    public void testBooleanEndOfStream() throws IOException {

	byte[] testData = {};
	BZip2BitInputStream inputStream = new BZip2BitInputStream(new ByteArrayInputStream(testData));

	inputStream.readBoolean();

    }

    // Unary

    /**
     * Test reading unary 0
     * 
     * @throws IOException
     */
    @Test
    public void testUnaryZero() throws IOException {

	byte[] testData = { 0x00 };
	BZip2BitInputStream inputStream = new BZip2BitInputStream(new ByteArrayInputStream(testData));

	assertEquals(0, inputStream.readUnary());

    }

    /**
     * Test reading unary 0
     * 
     * @throws IOException
     */
    @Test
    public void testUnaryOne() throws IOException {

	byte[] testData = { (byte) (1 << 7) };
	BZip2BitInputStream inputStream = new BZip2BitInputStream(new ByteArrayInputStream(testData));

	assertEquals(1, inputStream.readUnary());

    }

    /**
     * Test reading unary 0
     * 
     * @throws IOException
     */
    @Test
    public void testUnary31() throws IOException {

	byte[] testData = { (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xfe };
	BZip2BitInputStream inputStream = new BZip2BitInputStream(new ByteArrayInputStream(testData));

	assertEquals(31, inputStream.readUnary());

    }

    /**
     * Test reaching the end of the stream reading a unary number
     * 
     * @throws IOException
     */
    @Test(expected = IOException.class)
    public void testUnaryEndOfStream() throws IOException {

	byte[] testData = {};
	BZip2BitInputStream inputStream = new BZip2BitInputStream(new ByteArrayInputStream(testData));

	inputStream.readUnary();

    }

    // Bits
    /**
     * Test reading a single 0 as bits
     * 
     * @throws IOException
     */
    @Test
    public void testBits1_0() throws IOException {

	byte[] testData = { (byte) 0x00 };
	BZip2BitInputStream inputStream = new BZip2BitInputStream(new ByteArrayInputStream(testData));

	assertEquals(0, inputStream.readBits(1));

    }

    /**
     * Test reading a single 1 as bits
     * 
     * @throws IOException
     */
    @Test
    public void testBits1_1() throws IOException {

	byte[] testData = { (byte) (1 << 7) };
	BZip2BitInputStream inputStream = new BZip2BitInputStream(new ByteArrayInputStream(testData));

	assertEquals(1, inputStream.readBits(1));

    }

    /**
     * Test reading 23 bits
     * 
     * @throws IOException
     */
    @Test
    public void testBits23() throws IOException {

	byte[] testData = { 0x02, 0x03, 0x04 };
	BZip2BitInputStream inputStream = new BZip2BitInputStream(new ByteArrayInputStream(testData));

	assertEquals(0x020304 >> 1, inputStream.readBits(23));

    }

    /**
     * Test reaching the end of the stream reading bits
     * 
     * @throws IOException
     */
    @Test(expected = IOException.class)
    public void testBitsEndOfStream() throws IOException {

	byte[] testData = {};
	BZip2BitInputStream inputStream = new BZip2BitInputStream(new ByteArrayInputStream(testData));

	inputStream.readBits(1);

    }

    // Integer

    /**
     * Test reading an integer
     * 
     * @throws IOException
     */
    @Test
    public void testInteger() throws IOException {

	byte[] testData = { 0x12, 0x34, 0x56, 0x78 };
	BZip2BitInputStream inputStream = new BZip2BitInputStream(new ByteArrayInputStream(testData));

	assertEquals(0x12345678, inputStream.readInteger());

    }

    /**
     * Test reaching the end of the stream reading an integer
     * 
     * @throws IOException
     */
    @Test(expected = IOException.class)
    public void testIntegerEndOfStream() throws IOException {

	byte[] testData = {};
	BZip2BitInputStream inputStream = new BZip2BitInputStream(new ByteArrayInputStream(testData));

	inputStream.readInteger();

    }

}